DE10115245A1 - Pourable curable fat (meth) acrylates - Google Patents

Abstract

Production of new fatty (meth)acrylates (I) with an epoxide content 0.6%, comprises reacting (meth)acrylic acid with an epoxidized fatty acid ester or triglyceride that has an epoxide content of 6.4% and is derived from a fatty acid ester or triglyceride comprising 60 mole% of fatty acid units with two double bonds and less than 20 mole% of fatty acid units with three of more double bonds.

Description

Field of the Invention

The present invention relates to pourable curable fat (meth) acrylates and their Use for the production of coatings.

State of the art

The use of radiation curing in the coating industry for production high-quality coating materials are known from the prior art. Here olefinically unsaturated compounds (monomers, oligomers, polymers, Prepolymers), that is to say compounds which act as structural elements C = C double bonds contain, by the action of high-energy radiation, for example UV light o of electron radiation, hardened. Occasionally, this will actually Radiation curing also made physical drying.

US-A-3,979,270 describes in column 2, lines 4 to 21, the conversion of epoxi soybean oil with acrylic or methacrylic acid. The products obtained in the process one can call fat (meth) acrylates, are a subsequent hardening accessible to polymers, which can be realized in different ways.  

A disadvantage of the fat (meth) acrylates known from the prior art is in the fact that with increasing iodine number of these compounds on which they are based Fat or oils the viscosity of the fat (meth) acrylates increases sharply.

Soybean oil acrylate, for example, has a viscosity that is low enough in practice to handle well be available, but the resulting polymers from soybean oil acrylate only moderate degrees of hardness. On the other hand, he has polymerized linseed oil acrylate wishes high degrees of hardness, but linseed oil acrylate has an extremely high viscosity which is considerably too large for practical use to be able to handle the substance.

Description of the invention

The object of the present invention was to provide pourable curable Substances. On the one hand, these substances should have a viscosity of less than 30,000 mPas, and preferably less than 20,000 mPas (measured in sub stamped according to Brookfield at 23 ° C) and at the same time is characterized by this that they are used in the radical initiated curing (carried out in the presence of 5 wt .-% - based on the substance - tert-butyl peroxide benzoate at 160 ° C in egg a period of 30 minutes) to a polymer with a Shore D hardness (be is correct at 23 ° C according to DIN 53505) of at least 60. These two are the same Conditions to be met in good time mean that the substances are good on the one hand manageable, d. H. due to their relatively low viscosity especially pourable and / or should be pumpable, on the other hand in the case of radically initiated curing to polymers with the desired high hardness (Shore D values of at least 60 at 23 ° C).

The stated object was surprisingly achieved by means of fatty (meth) acrylates, obtainable by reacting epoxidized fatty acid esters and / or epoxidized triglycerides with acrylic acid and / or methacrylic acid, the reaction being carried out in such a way that the% -EpO content of the fat (meth) acrylates is below 0.6 and the following requirements apply to the epoxidized fatty acid esters and / or epoxidized triglycerides on which the fatty (meth) acrylates are based:

• a) The% EPO content of the epoxidized fatty acid esters and / or epoxy used dated triglycerides is above 6.4.
• b) Less than 20 mol% of the epoxidized fatty acid esters and / or epoxidized Triglyceride-based fatty acid building blocks contain 3 or more C = C double bonds per fatty acid building block.
• c) More than 60 mol% of the epoxidized fatty acid esters and / or epoxidized Fatty acid building blocks on which triglycerides are based contain 2 C = C- Double bonds per fatty acid building block.

Fat (meth) acrylates include both fat acrylates and fatty methacrylates understand. Fat acrylates and fatty methacrylates can be used within the scope of the present Invention both as individual substances, as well as in a mixture with each other be set. Both mixtures of fat acrylates and mixtures can be used of fatty methacrylates are used. Mixtures can also be used those that contain both fat acrylates and fatty methacrylates.

Regarding a)

The epoxy number (% EpO content) known to the person skilled in the art indicates how many grams Oxirane oxygen is contained in 100 grams of a sample. The epoxy number will determined by titration. Please refer to the example section where the measurement method to be used in the context of this invention is shown in detail is.

In one embodiment, the% EpO content of the epoxidized used Fatty acid esters and / or epoxidized triglycerides above 7.0.  

Regarding b)

In one embodiment, less than 10 mol% contain the epoxidized Fatty acid esters and / or epoxidized triglycerides underlying fatty acid Building blocks 3 or more C = C double bonds per fatty acid building block.

In a preferred embodiment, less than 5 mol% of the contain the epo based on oxidized fatty acid esters and / or epoxidized triglycerides Fatty acid building blocks 3 or more C = C double bonds per fatty acid building block.

Regarding c)

In one embodiment, more than 65 mol% contain the epoxidized fat esters and / or epoxidized triglycerides underlying fatty acid building blocks 2 C = C double bonds per fatty acid building block.

In a preferred embodiment, more than 70 mol% of the ep based on oxidized fatty acid esters and / or epoxidized triglycerides Fatty acid building blocks 2 C = C double bonds per fatty acid building block.

An optional embodiment of the invention is characterized in that less than 20 mol% - preferably less than 10 mol% - of the epoxidized Fatty acid esters and / or epoxidized triglycerides underlying fatty acid Building blocks are free of C = C double bonds, in the sense that these are Fatty acid building blocks are saturated fatty acids.

For the production of fat (meth) acrylates

As already stated, the invention relates to a first embodiment on fat (meth) acrylates, which are obtainable by reacting epoxidized fet esters and / or epoxidized triglycerides with acrylic acid and / or methacrylic acid.  The% -EpO content of the fatty (meth) acrylates should be below 0.6 can be set.

If epoxidized fet for the production of the fat (meth) acrylates according to the invention esters and / or epoxidized triglycerides with acrylic acid and / or methacrylic acid are implemented, the condition mentioned means that the in the off materials, namely the epoxidized fatty acid esters and / or epoxidized tri Oxirane rings present in glycerides are largely ring-opened. preference The oxirane ring opening is carried out almost quantitatively.

The production of epoxidized fatty acid esters or epoxidized triglycerides has been around since known for a long time. For this purpose, esters of olefinically unsaturated fatty acids or Triglycerides, which contain olefinically unsaturated fatty acids as fatty acid building blocks ten, subjected to epoxidation, one or more double bonds per Molecule can be converted into oxirane groups.

Carboxylic acids are included as fatty acid building blocks of the fatty acid esters to be epoxidized 12 to 24 carbon atoms, at least one olefinic double bond in the molecule included, preferred. With the triglycerides to be epoxidized there are such triglycides ride preferred, in which at least one fatty acid building block per triglyceride molecule contains at least one olefinic double bond.

Examples of suitable epoxidized triglycerides are the epoxidation products fol gender unsaturated oils: linola oil, hemp oil, ball thistle oil, safflower oil, sun flower oil, grape seed oil, poppy seed oil, spruce seed oil. Linola oil is very good here particularly preferred.

Epoxidized triglycerides are produced in particular by reaction the unsaturated oils mentioned with performic or peracetic acid.  

The addition of acrylic and / or methacrylic acid to the epoxidized Fatty acid esters or epoxidized triglycerides are known per se to the person skilled in the art. she is to be carried out in the context of the present invention so that the% EpO content the fat (meth) acrylate is below 0.6.

As already mentioned, however, it is particularly preferred to carry out the addition of acrylic and / or methacrylic acid to the epoxidized fatty acid esters or epoxidized triglycerides mentioned in such a way that more or less all the oxi ran rings are opened and in HO-CH ₂ -CH ₂ -OR groups are transferred in which R is an acrylate or methacrylate radical.

Use for the production of coating compositions

The fat (meth) acrylates according to the invention are outstandingly suitable for Production of coating compositions since they are curable substances zen acts.

Another object of the invention is accordingly the use of Fat (meth) acrylates according to the invention for the production of coating compositions.

The curing of the fatty (meth) acrylates according to the invention can be done both radi take place calically, which is due to the double bond contained in the molecules gene is possible. The curing can also be carried out by reaction with isocyanates gene because the molecules have free OH groups due to the oxirane ring opening.

It is also possible to subject one or more fatty (meth) acrylates to a two-stage treatment, namely

• - First a reaction with aliphatic and / or aromatic isocyanates  
• - and then a radical post-crosslinking of the Po obtained lyurethane (pu *) in the presence of at least one radical initiator.

In this respect, an implementation in the curing of the fatty (meth) acrylates according to the invention tion with isocyanates, the choice of isocyanates is not subject to any special restrictions. In principle, therefore, all can be the expert known isocyanates, ie compounds which contain one or more -N = C = O- Contain groups, insert.

Diisocyanates, oligo- or polyisocyanates, and mixtures are preferably used of these connections. About the polyisocyanates in the sense of the present invention adducts of diisocyanates with trimethylolpropane, Biurete, uretdiones (cyclodimerized isocyanates), isocyanurates (cyclotrimerized Isocyanates), allophanates, carbodiimide-based isocyanates and the like.

Special mention is made of commercially available polyisocyanates, for example Po lymer-MDI and the like, which come in different degrees of polymerization are available.

The diisocyanates are preferably compounds of the general Structure O = C = N-X-N = C = O a, where X is an aliphatic, alicyclic or aro is a radical, preferably an aliphatic or alicyclic radical with 4 to 18 carbon atoms.

Suitable diisocyanates are, for example: 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate (= methylene diphenylene diisocyanate, MDI), hydrogenated MDI (H ₁₂ MDI, a cyloaliphatic compound), xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI 4,4'-diphenyldimethylmethane diisocyanate, di- and tetraalkyldiphenylmethane diisocyanate, 4,4'-dibenzyl diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, the isomers of tolylene diisocyanate (TDI, especially the technical isomer mixture of essentially 2.4 - and 2,6-tolylene diisocyanate), 1-methyl-2,4-diisocyanato cyclohexane, 1,6-diisocyanato-2,2,4-trimethylhexane, 1,6-diisocyanato-2,4,4-trimethylhexane, 1-isocyanatomethyl-3-isocyanato-1,5,5-trimethyl-cyclohexane (isophorone diisocyanate = IPDI), chlorinated and brominated diisocyanates, phosphorus-containing diisocyanates, 4,4'-diisocyanatophenylperfluoroethane, tetramethoxybutane-1,4-diisocyanate, butane 1,4-diisocyanate, hexamethylene diisocyanate (HDI), dicyclohexylme thane diisocyanate, cyclohexane-1,4-diisocyanate, ethylene diisocyanate, phthalic acid re-bis-isocyanatoethyl ester, also diisocyanates with reactive halogen atoms, such as 1-chloromethylphenyl-2,4-diisocyanate, 1-bromomethylphenyl-2,6-diisocyanate, 3 , 3-bis-chloromethyl ether-4,4'-diphenyl diisocyanate. Sulfur-containing polyisocyanates are obtained, for example, by reacting 2 mol of hexamethylene diisocyanate with 1 mol of thiodiglycol or dihydroxydihexyl sulfide. Other important diisocyanates are trimethylhexamethylene diisocyanate, 1,4-diisocyanatobutane, 1,12-diisocyanatododecane and dimer fatty acid diisocyanate (commercial product "So vermol DDI 1410" from Cognis Deutschland GmbH).

Particularly suitable diisocyanates are: tetramethylene, hexamethylene, undecane, Dodecamethylene, 2,2,4-trimethylhexane, 1,3-cyclohexane, 1,4-cyclohexane, 1,3- or 1,4-tetramethylxylene, isophorone, 4,4-dicyclohexylmethane and lysine ester Diisocyanate.

In one embodiment of the present invention, more functional ones are used Isocyanates, which is understood to mean those isocyanates that have a medium Have NCO functionality of at least 2.0. In particular, be on everyone here commercially available polyisocyanates (for example polymer MDI and the like) referenced, which have an NCO functionality above 2.0. Like that Known to those skilled in the art, one speaks of medium NCO functionality because this corresponds to corresponding higher-functional isocyanates are not necessarily in the form of chemically uniform individuals such as cyclotrimerized isocyanates, but  - Especially with commercial technical products - often mixtures ver different chemical individuals, each with defined NCO Have functionalities.

compositions

Another subject of the invention relates to pourable, curable compositions Containing one or more fatty (meth) acrylates. In an execution tion form contain these compositions in addition to the invention Fat (meth) acrylates one or more radical copolymerizable compounds Gen. Such compounds are particularly suitable with substances a C = C double bond per molecule, preferably acrolein, acrylamide, vinyl acetate and styrene, these compounds alone or in a mixture with one another can be used.

In one embodiment, the fat (meth) acrylates according to the invention the - if desired in combination with radical copolymerizable ver bindings - in the presence of up to 20% by weight of conventional plastic auxiliaries Cured to form coating compositions (% by weight of the total of all art auxiliary substances based on the total amount of fat (meth) acrylates used). Such plastic auxiliaries are, for example, thickeners, flow aids medium, defoamers, lubricants, fillers, UV stabilizers. Such tools are adequately skilled in the art of coating or coating technology known.

As solid substrates on which the coating compositions according to the present invention can be applied, wood, paper, art are particularly suitable fabric surfaces, mineral building materials such as cement blocks or cement fa water plates, also metals or coated metals.  

The coating compositions are applied in a known manner to the desired solid substrate, for example by spraying, filling, knife coating, brushing, rolling or pouring. The coating thickness is generally in the range from 3 to 500 g / m ² and in particular 10 to 200 g / m ² or wet film thicknesses of about 3 to 500 μm and in particular 50 to 200 μm. The application can take place both at room temperature and at elevated temperature, but especially not above 100 ° C.

Examples A) Measurement methods Shore D hardness

The Shore D hardness was determined in accordance with DIN 53505 at 23 ° C.

As described above, the substances whose Shore D Hardness was measured by radically initiated hardening (carried out in the presence of 5 wt .-% - based on the sub punch - tert-butyl peroxide benzoate at 160 ° C in one period of 30 minutes) of the fatty (meth) acrylates according to the invention posed.

% EpO

To characterize the content of oxi compounds rank groups ("epoxy groups") was subjected to epoxy titration guided. The epoxy number obtained (% EpO) indicates how much Gram of oxirane oxygen contained in 100 grams of a sample are.

The titration is based on the following principle: You add one Solution with excess tetraethylammonium bromide for the pro be, which contains oxirane rings. Then titrate the mixture a solution of perchloric acid in glacial acetic acid, taking an equimola re amount of hydrogen bromide is released. The hydrogen bromide reacts with the ring opening and forms the oxirane rings corresponding bromohydrin.  

Crystal violet is used as an indicator. The determination sets the absence of water, bases and amines.

The following reagents were used: (1) 0.1-N- Perchloric acid (Merck) in glacial acetic acid; (2) Tetraethylammoni umbromide (from Fluka) in the form of a solution of 100 g Tetraethylammonium bromide in 400 ml glacial acetic acid; (3) crystal violet (Merck); 0.2 g were used to prepare the indicator solution Crystal violet dissolved in 100 ml glacial acetic acid.

execution

0.2 to 0.5 g of the sample containing oxirane rings are placed in an Erlenmeyer flask. The sample is in 50 ml of anhydrous acetone dissolved. Then add 10 ml Tetraethylammonium bromide solution (see above) and 3 drops Add crystal violet solution (see above). The mixture comes with a 0.1 N solution of perchloric acid in glacial acetic acid. The The end point is reached as soon as the color changes from blue to green changes.

Before carrying out the actual titration, one is carried out Blank sample through (this contains no oxirane compound) to Exclude measurement errors.

evaluation

The% EpO epoxy content is calculated as follows:

% EpO = [(a - b) .0.160] / E

a: = milliliter 0.1 n HClO ₄ solution required for titration
b: = milliliter 0.1 n HClO ₄ solution, which is required in the blind test
E: = sample weight in grams

B) Production and testing of fat acrylates

Table 1

Key figures of the oils used

In order to obtain good material properties, epoxidized fats and oils were used the maximum achievable oxirane content used.

In the case of epoxidized linseed oil and hemp oil, this was approximately 8.2% EpO, since at higher levels will solidify. For epoxidized linola oil this was Epoxy content approx.7.1% EpO and for epoxidized soybean oil approx.6.5% EpO.

Comparative Example 1 Soybean Oil Acrylate (V 1)

To a mixture of 1636 g soybean oil epoxide (% EpO = 6.3), 30 g triethylamine and 6000 ppm of hydroquinone methyl ether (MEHQ) were added over 10 hours at 130 ° C 465 g acrylic acid with vigorous stirring and introducing oxygen dropwise. The reaction was stopped when the acid number was less than 50.

The product had a% EpO value of 0.4.  

Comparative Example 2 Linseed oil acrylate (V 2)

To a mixture of 1000 g linseed oil epoxide (% EpO = 8.5), 30 g triethylamine and 6000 ppm MEHQ were 394 g acrylic acid over a period of 10 hours at 130 ° C added dropwise while stirring vigorously and introducing oxygen. The reaction was stopped when the acid number was less than 50.

The product had a% EpO value of 0.5

example 1 Linola oil acrylate (B1)

To a mixture of 1195 g linola oil epoxy (epoxy number = 7.1), 30 g triethyla min and 6000 ppm MEHQ became 382 g of acrylic in the course of 10 h at 130 ° C. acid was added dropwise while stirring vigorously and introducing oxygen. The reaction was stopped when the acid number was less than 50.

The product had a% EpO value of 0.4.

Application studies

As a measure of the properties of the fet that can be achieved in the hardened polymer These were tacrylates together with 5% by weight of tert-butyl peroxybenzoate Cured at 160 ° C for 30 min. The results are summarized in Table 2.

Table 2 clearly shows that the two formulated the task Conditions, namely the provision of pourable curable substances, which one partly a viscosity of less than 30,000 mPas and preferably less than 20,000 mPas (measured in Brookfield substance at 23 ° C) and  should at the same time be characterized by the fact that they initiated radicals in the Curing (carried out in the presence of 5% by weight, based on the substance) tert-butyl peroxide benzoate at 160 ° C in a period of 30 minutes) to one Polymers with a Shore D hardness (determined at 23 ° C according to DIN 53505) of lead at least 60, only achieved by example B 1 according to the invention, not however from the comparative examples.

Table 2

Claims (4)

1. Fat (meth) acrylates, obtainable by reacting epoxidized fatty acid esters and / or epoxidized triglycerides with acrylic acid and / or methacrylic acid, the reaction being carried out in such a way that the% -EpO content of the fatty (meth) acrylates is below 0. 6 and the following requirements apply to the epoxidized fatty acid esters and / or epoxidized triglycerides on which the fatty (meth) acrylates are based:

• a) The% EPO content of the epoxidized fatty acid esters and / or epoxidized triglycerides used is above 6.4.
• b) Less than 20 mol% of the fatty acid units on which the epoxidized fatty acid esters and / or epoxidized triglycerides are based contain 3 or more C = C double bonds per fatty acid unit.
• c) More than 60 mol% of the fatty acid units on which the epoxidized fatty acid esters and / or epoxidized triglycerides are based contain 2 C = C double bonds per fatty acid unit.

2. Use of fat (meth) acrylates according to claim 1 for the preparation of Be coating masses. 3. Pourable, curable compositions containing one or more reren fat (meth) acrylates according to claim 1. 4. Compositions according to claim 3, wherein additionally with the Fat (meth) acrylates containing free-radically copolymerizable compounds.